Tissue loading of a surgical instrument

ABSTRACT

Various ultrasonic instruments are disclosed. The ultrasonic instruments include structures configured to indicate the cutting length of the instruments, detect when grasped tissue has extended beyond the cutting length of the instrument, and prevent tissue from extending beyond the cutting length. Several techniques for each types of structures are disclosed.

PRIORITY

This application claims the benefit of U.S. Provisional Application Ser. No. 62/379,550 filed Aug. 25, 2016, which is incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates, in general, to ultrasonic surgical instruments and more particularly to ultrasonic transducers to drive ultrasonic waveguides. Ultrasonic instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic instruments, and particularly solid core ultrasonic instruments, are advantageous because they may be used to cut and/or coagulate organic tissue using energy in the form of mechanical vibrations transmitted to a surgical end effector at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to organic tissue at suitable energy levels and using a suitable end effector, may be used to cut, dissect, elevate or cauterize tissue or to separate muscle tissue from bone. Ultrasonic instruments utilizing solid core technology are particularly advantageous because of the amount of ultrasonic energy that may be transmitted from the ultrasonic transducer, through a waveguide, and to the surgical end effector. Such instruments may be used for open procedures or minimally invasive procedures, such as endoscopic or laparoscopic procedures, wherein the end effector is passed through a trocar to reach the surgical site.

Activating or exciting the end effector (e.g., cutting blade) of such instruments at ultrasonic frequencies induces longitudinal vibratory movement that generates localized heat within adjacent tissue. Because of the nature of ultrasonic instruments, a particular ultrasonically actuated end effector may be designed to perform numerous functions, including, for example, cutting and coagulation. Ultrasonic vibration is induced in the surgical end effector by electrically exciting a transducer, for example. The transducer may be constructed of one or more piezoelectric or magnetostrictive elements in the instrument hand piece. Vibrations generated by the transducer are transmitted to the surgical end effector via an ultrasonic waveguide extending from the transducer to the surgical end effector. The waveguide and end effector are designed to resonate at the same frequency as the transducer. Therefore, when an end effector is attached to a transducer, the overall system frequency is the same frequency as the transducer itself.

The amplitude of the longitudinal ultrasonic vibration at the tip, d, of the end effector behaves as a simple sinusoid at the resonant frequency as given by: d=A sin(ωt) where:

ω=the radian frequency which equals 2π times the cyclic frequency, f; and

A=the zero-to-peak amplitude.

The longitudinal excursion of the end effector tip is defined as the peak-to-peak (p-t-p) amplitude, which is just twice the amplitude of the sine wave or 2A. Often, the end effector can comprise a blade which, owing to the longitudinal excursion, can cut and/or coagulate tissue. U.S. Pat. No. 6,283,981, which issued on Sep. 4, 2001 and is entitled METHOD OF BALANCING ASYMMETRIC ULTRASONIC SURGICAL BLADES; U.S. Pat. No. 6,309,400, which issued on Oct. 30, 2001 and is entitled CURVED ULTRASONIC WAVEGUIDE HAVING A TRAPEZOIDAL CROSS SECTION; and U.S. Pat. No. 6,436,115, which issued on Aug. 20, 2002 and is entitled BALANCED ULTRASONIC WAVEGUIDE INCLUDING A PLURALITY OF BALANCE ASYMMETRIES, the entire disclosures of which are hereby incorporated by reference herein, disclose various ultrasonic surgical instruments.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

SUMMARY

In one general aspect, various aspects are directed to an ultrasonic surgical instrument that comprises a transducer configured to produce vibrations along a longitudinal axis of a surgical instrument at a predetermined frequency. In various aspects, the surgical instrument may include an ultrasonic waveguide that extends along the longitudinal axis and is coupled to the transducer. In various aspects, the surgical instrument includes a body having a proximal end and a distal end, wherein the distal end is movable relative to the longitudinal axis by the vibrations produced by the transducer, and the proximal end is mechanically coupled to the transducer.

In one aspect, an ultrasonic surgical instrument is provided. The ultrasonic surgical instrument comprises an end effector; a jaw movable relative to the end effector; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and an indicium coextensive with a portion of the jaw overlying the end effector.

In another aspect, an ultrasonic surgical instrument is provided. The ultrasonic surgical instrument comprises an end effector; a jaw movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and a cam movably connected to the jaw via a linkage; wherein in the jaw closed position, the cam is configured to extend towards a proximal end of the jaw; and wherein in the jaw open position, the cam is configured to retract.

In another aspect, an ultrasonic surgical instrument is provided. The ultrasonic surgical instrument comprises an end effector; a jaw movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; a slidable member movable between a retracted position and an extended position, wherein in the slidable member extended position the slidable member is configured to contact a proximal end of the jaw; wherein the member is biased to the retracted position; and a projection, wherein in the jaw closed position the projection is configured to contact the spring-biased member, and wherein in the jaw closed position the projection is configured to move the slidable member to the extended position.

In another aspect, an ultrasonic surgical instrument is provided. The ultrasonic surgical instrument comprises a first arm; a second arm pivotably connected to the first arm; a jaw disposed at a distal end of the first arm; an end effector disposed at a distal end of the second arm; wherein the jaw is movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and a bar member extending from the second arm through the first arm at a position proximal to the jaw, the bar member comprising a curvature corresponding to a rotational arc of the first arm.

FIGURES

The features of various aspects are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows.

FIG. 1 illustrates an ultrasonic surgical instrument system, according to one aspect of this disclosure.

FIGS. 2A-2C illustrate a piezoelectric transducer, according to one aspect of this disclosure.

FIG. 3 illustrates a D31 ultrasonic transducer architecture that includes an ultrasonic waveguide and one or more piezoelectric elements fixed to the ultrasonic waveguide, according to one aspect of this disclosure.

FIG. 4 illustrates a perspective view of an ultrasonic surgical instrument, according to one aspect of this disclosure.

FIG. 5 illustrates a cutaway view of the ultrasonic surgical instrument in FIG. 4, according to one aspect of this disclosure.

FIG. 6 illustrates a cutaway view of the ultrasonic surgical instrument in FIG. 4, wherein the ultrasonic surgical instrument is in an open position, according to one aspect of this disclosure.

FIG. 7 illustrates an exploded view of the ultrasonic surgical instrument in FIG. 4, according to one aspect of this disclosure.

FIG. 8 illustrates a sectional view of the ultrasonic surgical instrument in FIG. 4 along line 8-8, according to one aspect of this disclosure.

FIG. 9 illustrates a detail view of the jaw and end effector portions of the ultrasonic surgical instrument in FIG. 4, according to one aspect of this disclosure.

FIG. 10 illustrates a perspective view of the distal portion of an ultrasonic surgical instrument including a curved end effector, according to one aspect of this disclosure.

FIG. 11 illustrates a side view of the distal portion of the ultrasonic surgical instrument in FIG. 10, according to one aspect of this disclosure.

FIG. 12 illustrates a perspective view of an ultrasonic surgical instrument including a clip closure, according to one aspect of this disclosure.

FIG. 13 illustrates a side view of the distal portion of an ultrasonic surgical instrument configured to detect improper tissue clamping, according to one aspect of this disclosure.

FIG. 14 illustrates a side view of the ultrasonic surgical instrument in FIG. 13, according to one aspect of this disclosure.

FIG. 15 illustrates a perspective view of an end portion of an ultrasonic surgical instrument incorporating a pivotable member tissue stop, wherein the pivotable member is in a stowed position, according to one aspect of this disclosure.

FIG. 16 illustrates a perspective view of the end portion of the ultrasonic surgical instrument in FIG. 15, wherein the pivotable member is in the deployed position, according to one aspect of this disclosure.

FIG. 17 illustrates a perspective view of an ultrasonic surgical instrument incorporating a mechanical linkage tissue stop, according to one aspect of this disclosure.

FIG. 18 illustrates a side view of the ultrasonic surgical instrument in FIG. 17 in an open position, according to one aspect of this disclosure.

FIG. 19 illustrates a side view of the ultrasonic surgical instrument in FIG. 17 in a closed position, according to one aspect of this disclosure.

FIG. 20 illustrates a side view of an ultrasonic surgical instrument incorporating a deformable member tissue stop, according to one aspect of this disclosure.

FIG. 21 illustrates a side view of the ultrasonic surgical instrument in FIG. 20 in a partially clamped position, according to one aspect of this disclosure.

FIG. 22 illustrates a side view of the ultrasonic surgical instrument in FIG. 20 in a clamped position, according to one aspect of this disclosure.

FIG. 23 illustrates a perspective view of an ultrasonic surgical instrument incorporating a curved bar tissue stop, according to one aspect of this disclosure.

FIG. 24 illustrates a partial sectional view of the ultrasonic surgical instrument in FIG. 23, according to one aspect of this disclosure.

FIG. 25 illustrates a side view of the ultrasonic surgical instrument in FIG. 23 in an open position, according to one aspect of this disclosure.

FIG. 26 illustrates a side view of the ultrasonic surgical instrument in FIG. 23 in a closed position, according to one aspect of this disclosure.

FIG. 27 illustrates a perspective view of an ultrasonic surgical instrument incorporating an end effector ring tissue stop, according to one aspect of this disclosure.

FIG. 28 illustrates a side view of one aspect of the tissue stop in FIG. 27, according to one aspect of this disclosure.

FIG. 29 illustrates a front view of the tissue stop in FIG. 27, according to one aspect of this disclosure.

FIG. 30 illustrates a top view of one aspect of the tissue stop in FIG. 27, according to one aspect of this disclosure.

FIG. 31 illustrates a perspective view of an ultrasonic surgical instrument incorporating a longitudinally slidable member tissue stop, wherein the ultrasonic surgical instrument is in an open position, according to one aspect of this disclosure.

FIG. 32 illustrates a perspective view of the ultrasonic surgical instrument in FIG. 31 in a closed position, according to one aspect of this disclosure.

FIG. 33 illustrates a cutaway view of the longitudinally slidable member tissue stop in FIG. 31, according to one aspect of this disclosure.

FIG. 34 illustrates a side view of an ultrasonic surgical instrument incorporating a cam-actuated member tissue stop in an open position, according to one aspect of this disclosure.

FIG. 35 illustrates a side view of the ultrasonic surgical instrument in FIG. 37 in a closed position, according to one aspect of this disclosure.

FIG. 36 illustrates a perspective view of an ultrasonic surgical instrument incorporating a flexible strip tissue stop, according to one aspect of this disclosure.

FIG. 37 illustrates a perspective view of the ultrasonic surgical instrument in FIG. 36 in a closed position, according to one aspect of this disclosure.

FIG. 38 illustrates a perspective view of an ultrasonic surgical instrument incorporating a flexible strip tissue stop, according to one aspect of this disclosure.

FIG. 39 illustrates a side view of the ultrasonic surgical instrument in FIG. 38 in a closed position, according to one aspect of this disclosure.

FIG. 40 illustrates a side view of the ultrasonic surgical instrument in FIG. 38 in an open position, according to one aspect of this disclosure.

FIG. 41 illustrates a perspective view of an ultrasonic surgical instrument incorporating a flexible strip tissue stop, according to one aspect of this disclosure.

FIG. 42 illustrates a side view of the ultrasonic surgical instrument in FIG. 41 in a closed position, according to one aspect of this disclosure.

FIG. 43 illustrates a side view of the ultrasonic surgical instrument in FIG. 41 in an open position, according to one aspect of this disclosure.

DESCRIPTION

Before explaining various aspects in detail, it should be noted that such aspects are not limited in their application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative aspects may be implemented or incorporated in other aspects, variations and modifications, and may be practiced or carried out in various ways. For example, the surgical instruments disclosed below are illustrative only and not meant to limit the scope or application thereof. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative aspects for the convenience of the reader and are not to limit the scope thereof.

Certain aspects will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these aspects are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting examples aspects and that the scope of the various aspects is defined solely by the claims. The features illustrated or described in connection with one aspect may be combined with the features of other aspects. Such modifications and variations are intended to be included within the scope of the claims.

Various aspects described herein relate, in general, to ultrasonic surgical instruments and blades for use therewith. Examples of ultrasonic surgical instruments and blades are disclosed in U.S. Pat. Nos. 5,322,055; 5,954,736; 6,309,400; 6,278,218; 6,283,981; 6,325,811; and 8,319,400, wherein the entire disclosures of which are incorporated by reference herein.

According to various aspects, an ultrasonic instrument comprising a surgical instrument having an end effector such as a blade can be of particular benefit, among others, in orthopedic procedures where it is desirable to remove cortical bone and/or tissue while controlling bleeding. Due to its cutting and coagulation characteristics, a blade of an ultrasonic surgical instrument may be useful for general soft tissue cutting and coagulation. In certain circumstances, a blade according to various aspects may be useful to simultaneously cut and hemostatically seal or cauterize tissue. A blade may be straight or curved, and useful for either open or laparoscopic applications. A blade according to various aspects may be useful in spine surgery, especially to assist in posterior access in removing muscle from bone.

Applicant of the present application owns the following patent applications filed on Aug. 17, 2017 and which are each herein incorporated by reference in their respective entireties:

U.S. Patent Application Ser. No. 15/679,940 entitled “Ultrasonic Transducer Techniques for Ultrasonic Surgical Instrument” by inventors Jeffrey Messerly et al. filed Aug. 17, 2017.

U.S. patent application Ser. No. 15/679,948 entitled “Ultrasonic Transducer For Surgical Instrument, by inventors Jeffrey Messerly et al. filed Aug. 17, 2017.

U.S. patent application Ser. No. 15/679,952 entitled “Electrical And Thermal Connections For Ultrasonic Transducer” by inventors Jeffrey Messerly et al. filed Aug. 17, 2017.

U.S. patent application Ser. No. 15/679,959 entitled “Ultrasonic Transducer to Waveguide Acoustic Coupling, Connections, and Configurations” by inventors Jeffrey Messerly et al. filed Aug. 17, 2017.

U.S. patent application Ser. No. 15/679,960 entitled “Ultrasonic Transducer to Waveguide Joining” by inventors Jeffrey Messerly et al. filed Aug. 17, 2017.

FIG. 1 illustrates one aspect of an ultrasonic system 10. One aspect of the ultrasonic system 10 comprises an ultrasonic signal generator 12 coupled to an ultrasonic transducer 14, a hand piece assembly 60 comprising a hand piece housing 16, and an end effector 50. The ultrasonic transducer 14, which is known as a “Langevin stack,” generally includes a transduction portion 18, a first resonator or end-bell 20, and a second resonator or fore-bell 22, and ancillary components. In various aspects, the ultrasonic transducer 14 is preferably an integral number of one-half system wavelengths (nλ/2) in length as will be described in more detail below. An acoustic assembly 24 can include the ultrasonic transducer 14, a mount 26, a velocity transformer 28, and a surface 30.

It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a clinician gripping the hand piece assembly 60. Thus, the end effector 50 is distal with respect to the more proximal hand piece assembly 60. It will be further appreciated that, for convenience and clarity, spatial terms such as “top” and “bottom” also are used herein with respect to the clinician gripping the hand piece assembly 60. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.

The distal end of the end-bell 20 is connected to the proximal end of the transduction portion 18, and the proximal end of the fore-bell 22 is connected to the distal end of the transduction portion 18. The fore-bell 22 and the end-bell 20 have a length determined by a number of variables, including the thickness of the transduction portion 18, the density and modulus of elasticity of the material used to manufacture the end-bell 20 and the fore-bell 22, and the resonant frequency of the ultrasonic transducer 14. The fore-bell 22 may be tapered inwardly from its proximal end to its distal end to amplify the ultrasonic vibration amplitude of the velocity transformer 28, or, alternately, fore-bell 22 may have no amplification.

Referring again to FIG. 1, end-bell 20 can include a threaded member extending therefrom which can be configured to be threadably engaged with a threaded aperture in fore-bell 22. In various aspects, piezoelectric elements, such as piezoelectric elements 32, for example, can be compressed between end-bell 20 and fore-bell 22 when end-bell 20 and fore-bell 22 are assembled together. Piezoelectric elements 32 may be fabricated from any suitable material, such as, for example, lead zirconate-titanate, lead meta-niobate, lead titanate, and/or any suitable piezoelectric crystal material, for example.

In various aspects, as discussed in greater detail below, transducer 14 can further comprise electrodes, such as positive electrodes 34 and negative electrodes 36, for example, which can be configured to create a voltage potential across one or more piezoelectric elements 32. Each of the positive electrodes 34, negative electrodes 36, and the piezoelectric elements 32 can comprise a bore extending through the center which can be configured to receive the threaded member of end-bell 20. In various aspects, the positive and negative electrodes 34 and 36 are electrically coupled to wires 38 and 40, respectively, wherein the wires 38 and 40 can be encased within a cable 42 and electrically connectable to the ultrasonic signal generator 12 of the ultrasonic system 10.

In various aspects, the ultrasonic transducer 14 of the acoustic assembly 24 converts the electrical signal from the ultrasonic signal generator 12 into mechanical energy that results in primarily longitudinal vibratory motion of the ultrasonic transducer 14 and the end effector 50 at ultrasonic frequencies. A suitable generator is available as model number GEN11, from Ethicon Endo-Surgery, Inc., Cincinnati, Ohio. When the acoustic assembly 24 is energized, a vibratory motion standing wave is generated through the acoustic assembly 24. A suitable vibrational frequency range may be about 20 Hz to 120 kHz and a well-suited vibrational frequency range may be about 30-70 kHz and one example operational vibrational frequency may be approximately 55.5 kHz.

The amplitude of the vibratory motion at any point along the acoustic assembly 24 may depend upon the location along the acoustic assembly 24 at which the vibratory motion is measured. A minimum or zero crossing in the vibratory motion standing wave is generally referred to as a node (i.e., where motion is usually minimal), and an absolute value maximum or peak in the standing wave is generally referred to as an anti-node (i.e., where motion is usually maximal). The distance between an anti-node and its nearest node is one-quarter wavelength (λ/4).

As outlined above, the wires 38, 40 transmit an electrical signal from the ultrasonic signal generator 12 to the positive electrodes 34 and the negative electrodes 36. The piezoelectric elements 32 are energized by the electrical signal supplied from the ultrasonic signal generator 12 in response to a foot switch 44, for example, to produce an acoustic standing wave in the acoustic assembly 24. The electrical signal causes disturbances in the piezoelectric elements 32 in the form of repeated small displacements resulting in large compression forces within the material. The repeated small displacements cause the piezoelectric elements 32 to expand and contract in a continuous manner along the axis of the voltage gradient, producing longitudinal waves of ultrasonic energy.

In various aspects, the ultrasonic energy produced by transducer 14 can be transmitted through the acoustic assembly 24 to the end effector 50 via an ultrasonic transmission waveguide 46. In order for the acoustic assembly 24 to deliver energy to the end effector 50, the components of the acoustic assembly 24 are acoustically coupled to the end effector 50. For example, the distal end of the ultrasonic transducer 14 may be acoustically coupled at the surface 30 to the proximal end of the ultrasonic transmission waveguide 46 by a threaded connection such as a stud 48.

The components of the acoustic assembly 24 can be acoustically tuned such that the length of any assembly is an integral number of one-half wavelengths (nλ/2), where the wavelength λ is the wavelength of a pre-selected or operating longitudinal vibration drive frequency fd of the acoustic assembly 24, and where n is any positive integer. It is also contemplated that the acoustic assembly 24 may incorporate any suitable arrangement of acoustic elements.

The ultrasonic end effector 50 may have a length substantially equal to an integral multiple of one-half system wavelengths (λ/2). A distal end 52 of the ultrasonic end effector 50 may be disposed at, or at least near, an antinode in order to provide the maximum, or at least nearly maximum, longitudinal excursion of the distal end. When the transducer assembly is energized, in various aspects, the distal end 52 of the ultrasonic end effector 50 may be configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak and preferably in the range of approximately 30 to 150 microns at a predetermined vibrational frequency.

As outlined above, the ultrasonic end effector 50 may be coupled to the ultrasonic transmission waveguide 46. In various aspects, the ultrasonic end effector 50 and the ultrasonic transmission guide 46 as illustrated are formed as a single unit construction from a material suitable for transmission of ultrasonic energy such as, for example, Ti6Al4V (an alloy of titanium including aluminum and vanadium), aluminum, stainless steel, and/or any other suitable material. Alternately, the ultrasonic end effector 50 may be separable (and of differing composition) from the ultrasonic transmission waveguide 46, and coupled by, for example, a stud, weld, glue, quick connect, or other suitable known methods. The ultrasonic transmission waveguide 46 may have a length substantially equal to an integral number of one-half system wavelengths (λ/2), for example. The ultrasonic transmission waveguide 46 may be preferably fabricated from a solid core shaft constructed out of material that propagates ultrasonic energy efficiently, such as titanium alloy (i.e., Ti6Al4V) or an aluminum alloy, for example.

In the aspect illustrated in FIG. 1, the ultrasonic transmission waveguide 46 comprises a plurality of stabilizing silicone rings or compliant supports 56 positioned at, or at least near, a plurality of nodes. The silicone rings 56 can dampen undesirable vibration and isolate the ultrasonic energy from a sheath 58 at least partially surrounding waveguide 46, thereby assuring the flow of ultrasonic energy in a longitudinal direction to the distal end 52 of the end effector 50 with maximum efficiency.

As shown in FIG. 1, the sheath 58 can be coupled to the distal end of the handpiece assembly 60. The sheath 58 generally includes an adapter or nose cone 62 and an elongated tubular member 64. The tubular member 64 is attached to and/or extends from the adapter 62 and has an opening extending longitudinally therethrough. In various aspects, the sheath 58 may be threaded or snapped onto the distal end of the housing 16. In at least one aspect, the ultrasonic transmission waveguide 46 extends through the opening of the tubular member 64 and the silicone rings 56 can contact the sidewalls of the opening and isolate the ultrasonic transmission waveguide 46 therein. In various aspects, the adapter 62 of the sheath 58 is preferably constructed from Ultem®, for example, and the tubular member 64 is fabricated from stainless steel, for example. In at least one aspect, the ultrasonic transmission waveguide 46 may have polymeric material, for example, surrounding it in order to isolate it from outside contact.

As described above, a voltage, or power source can be operably coupled with one or more of the piezoelectric elements of a transducer, wherein a voltage potential applied to each of the piezoelectric elements can cause the piezoelectric elements to expand and contract, or vibrate, in a longitudinal direction. As also described above, the voltage potential can be cyclical and, in various aspects, the voltage potential can be cycled at a frequency which is the same as, or nearly the same as, the resonant frequency of the system of components comprising transducer 14, waveguide 46, and end effector 50, for example. In various aspects, however, certain of the piezoelectric elements within the transducer may contribute more to the standing wave of longitudinal vibrations than other piezoelectric elements within the transducer. More particularly, a longitudinal strain profile may develop within a transducer wherein the strain profile may control, or limit, the longitudinal displacements that some of the piezoelectric elements can contribute to the standing wave of vibrations, especially when the system is being vibrated at or near its resonant frequency.

It may be recognized, in reference to the ultrasonic surgical instrument system 10 of FIG. 1, that multiple components may be required to couple the mechanical vibrations from the piezoelectric elements 32 through the waveguide 46 to the end effector 50. The additional elements comprising the acoustic assembly 24 may add additional manufacturing costs, fabrication steps, and complexity to the system. Disclosed below are aspects of an ultrasonic surgical instrument that may require fewer components, manufacturing steps, and costs than the equivalent device illustrated in FIG. 1 and as disclosed above.

Again, referring to FIG. 1, the piezoelectric elements 32 are configured into a “Langevin stack,” in which the piezoelectric elements 32 and their activating electrodes 34 and 36 (together, transducer 14) are interleaved. The mechanical vibrations of the activated piezoelectric elements 32 propagate along the longitudinal axis of the transducer 14, and are coupled via the acoustic assembly 24 to the end of the waveguide 46. Such a mode of operation of a piezoelectric element is frequently described as the D33 mode of the element, especially for ceramic piezoelectric elements comprising, for example, lead zirconate-titanate, lead meta-niobate, or lead titanate. The D33 mode of a ceramic piezoelectric element is illustrated in FIGS. 2A-2C.

FIG. 2A depicts a piezoelectric element 200 fabricated from a ceramic piezoelectric material. A piezoelectric ceramic material is a polycrystalline material comprising a plurality of individual microcrystalline domains. Each microcrystalline domain possesses a polarization axis along which the domain may expand or contract in response to an imposed electric field. However, in a native ceramic, the polarization axes of the microcrystalline domains are arranged randomly, so there is no net piezoelectric effect in the bulk ceramic. A net re-orientation of the polarization axes may be induced by subjecting the ceramic to a temperature above the Curie temperature of the material and placing the material in a strong electrical field. Once the temperature of the sample is dropped below the Curie temperature, a majority of the individual polarization axes will be re-oriented and fixed in a bulk polarization direction. FIG. 2A illustrates such a piezoelectric element 200 after being polarized along the inducing electric field axis P. While the un-polarized piezoelectric element 200 lacks any net piezoelectric axis, the polarized element 200 can be described as possessing a polarization axis, d3, parallel to the inducing field axis P direction. For completeness, an axis orthogonal to the d3 axis may be termed a d1 axis. The dimensions of the piezoelectric element 200 are labeled as length (L), width (W), and thickness (T).

FIGS. 2B and 2C illustrate the mechanical deformations of a piezoelectric element 200 that may be induced by subjecting the piezoelectric element 200 to an actuating electrical field E oriented along the d3 (or P) axis. FIG. 2B illustrates the effect of an electric field E having the same direction as the polarization field P along the d3 axis on a piezoelectric element 205. As illustrated in FIG. 2B, the piezoelectric element 205 may deform by expanding along the d3 axis while compressing along the d1 axis. FIG. 2C illustrates the effect of an electric field E having the opposing direction to the polarization field P along the d3 axis on a piezoelectric element 210. As illustrated in FIG. 2C, the piezoelectric element 210 may deform by compressing along the d3 axis, while expanding along the d1 axis. Vibrational coupling along the d3 axis during the application of an electric field along the d3 axis may be termed D33 coupling or activation using a D33 mode of a piezoelectric element. The transducer 14 illustrated in FIG. 1 uses the D33 mode of the piezoelectric elements 32 for transmitting mechanical vibrations along the waveguide 46 to the end effector 50. Because the piezoelectric element also deforms along the d1 axis, vibrational coupling along the d1 axis during the application of an electric field along the d3 axis may also be an effective source of mechanical vibrations. Such coupling may be termed D31 coupling or activation using a D31 mode of a piezoelectric element.

As illustrated by FIGS. 2A-2C, during operation in the D31 mode, transverse expansion of piezoelectric elements 200, 205, 210 may be mathematically modeled by the following equation:

$\frac{\Delta\; L}{L} = {\frac{\Delta\; W}{W} = \frac{V_{d\; 31}}{T}}$

In the equation, L, W, and T refer to the length, width and thickness dimensions of a piezoelectric element, respectively. Vd31 denotes the voltage applied to a piezoelectric element operating in the D31 mode. The quantity of transverse expansion resulting from the D31 coupling described above is represented by ΔL (i.e. expansion of the piezoelectric element along the length dimension) and ΔW (i.e. expansion of the piezoelectric element along the width dimension). Additionally, the transverse expansion equation models the relationship between ΔL and ΔW and the applied voltage Vd31. Disclosed below are aspects of ultrasonic surgical instruments based on D31 activation by a piezoelectric element.

In various aspects, as described below, a ultrasonic surgical instrument can comprise a transducer configured to produce longitudinal vibrations, and a surgical instrument having a transducer base plate (e.g., a transducer mounting portion) operably coupled to the transducer, an end effector, and waveguide therebetween. In certain aspects, as also described below, the transducer can produce vibrations which can be transmitted to the end effector, wherein the vibrations can drive the transducer base plate, the waveguide, the end effector, and/or the other various components of the ultrasonic surgical instrument at, or near, a resonant frequency. In resonance, a longitudinal strain pattern, or longitudinal stress pattern, can develop within the transducer, the waveguide, and/or the end effector, for example. In various aspects, such a longitudinal strain pattern, or longitudinal stress pattern, can cause the longitudinal strain, or longitudinal stress, to vary along the length of the transducer base plate, waveguide, and/or end effector, in a sinusoidal, or at least substantially sinusoidal, manner. In at least one aspect, for example, the longitudinal strain pattern can have maximum peaks and zero points, wherein the strain values can vary in a non-linear manner between such peaks and zero points.

FIG. 3 illustrates an ultrasonic surgical instrument 250 that includes an ultrasonic waveguide 252 attached to an ultrasonic transducer 264 by a bonding material, where the ultrasonic surgical instrument 250 is configured to operate in a D31 mode, according to one aspect of this disclosure. The ultrasonic transducer 264 includes first and second piezoelectric elements 254 a, 254 b attached to the ultrasonic waveguide 252 by a bonding material. The piezoelectric elements 254 a, 254 b include electrically conductive plates 256 a, 256 b to electrically couple one pole of a voltage source suitable to drive the piezoelectric elements 254 a, 254 b (e.g., usually a high voltage). The opposite pole of the voltage source is electrically coupled to the ultrasonic waveguide 252 by electrically conductive joints 258 a, 258 b. In one aspect, the electrically conductive plates 256 a, 256 b are coupled to a positive pole of the voltage source and the electrically conductive joints 258 a, 258 b are electrically coupled to ground potential through the metal ultrasonic waveguide 252. In one aspect, the ultrasonic waveguide 252 is made of titanium or titanium alloy (i.e., Ti6Al4V) and the piezoelectric elements 254 a, 254 b are made of a lead zirconate titanate intermetallic inorganic compound with the chemical formula Pb[ZrxTi1-x]O3 (0≤x≤1). Also called PZT, it is a ceramic perovskite material that shows a marked piezoelectric effect, meaning that the compound changes shape when an electric field is applied. It is used in a number of practical applications such as ultrasonic transducers and piezoelectric resonators PZT. The poling axis (P) of the piezoelectric elements 254 a, 254 b is indicated by the direction arrow 260. The motion axis of the ultrasonic waveguide 252 in response to excitation of the piezoelectric elements 254 a, 245 b is shown by a motion arrow 262 at the distal end of the ultrasonic waveguide 252 generally referred to as the ultrasonic blade portion of the ultrasonic waveguide 252. The motion axis 262 is orthogonal to the poling axis (P) 260.

In conventional D33 ultrasonic transducer architectures as shown in FIG. 1, the bolted piezoelectric elements 32 utilize electrodes 34, 36 to create electrical contact to both sizes of each piezoelectric element 33. The D31 architecture 250 according to one aspect of this disclosure, however, employs a different technique to create electrical contact to both sides of each piezoelectric element 254 a, 254 b. Various techniques for providing electrical contact to the piezoelectric elements 254 a, 254 b include bonding electrical conductive elements (e.g., wires) to the free surface of each piezoelectric element 254 a, 254 b for the high potential connection and bonding each piezoelectric element 254 a, 254 b the to the ultrasonic waveguide 252 for the ground connection using solder, conductive epoxy, or other techniques described herein. Compression can be used to maintain electrical contact to the acoustic train without making a permanent connection. This can cause an increase in device thickness and should be controlled to avoid damaging the piezoelectric elements 254 a, 254 b. Low compression can damage the piezoelectric element 254 a, 254 b by a spark gap and high compression can damage the piezoelectric elements 254 a, 254 b by local mechanical wear. In other techniques, metallic spring contacts may be employed to create electrical contact with the piezoelectric elements 254 a, 254 b. Other techniques may include foil-over-foam gaskets, conductive foam, solder. Electrical connection to both sides of the piezoelectric elements 254 a, 254 b the D31 acoustic train configuration. The electrical ground connection can be made to the metal ultrasonic waveguide 252, which is electrically conductive, if there is electrical contact between the piezoelectric elements 254 a, 254 b and the ultrasonic waveguide 252.

In various aspects, as described below, an ultrasonic surgical instrument may comprise a transducer configured to produce longitudinal vibrations, and a surgical instrument having a transducer base plate operably coupled to the transducer, an end effector, and waveguide therebetween. In certain aspects, as also described below, the transducer can produce vibrations which can be transmitted to the end effector, wherein the vibrations can drive the transducer base plate, the waveguide, the end effector, and/or the other various components of the ultrasonic surgical instrument at, or near, a resonant frequency. In resonance, a longitudinal strain pattern, or longitudinal stress pattern, can develop within the transducer, the waveguide, and/or the end effector, for example. In various aspects, such a longitudinal strain pattern, or longitudinal stress pattern, can cause the longitudinal strain, or longitudinal stress, to vary along the length of the transducer base plate, waveguide, and/or end effector, in a sinusoidal, or at least substantially sinusoidal, manner. In at least one aspect, for example, the longitudinal strain pattern can have maximum peaks and zero points, wherein the strain values can vary in a non-linear manner between such peaks and zero points.

In conventional D33 ultrasonic transducer architectures as shown in FIG. 1, a bolt provides compression that acoustically couples the piezoelectric elements rings to the ultrasonic waveguide. The D31 architecture 250 according to one aspect of this disclosure employs a variety of different techniques to acoustically couple the piezoelectric elements 254 a, 254 b to the ultrasonic waveguide 252. These techniques are disclosed hereinbelow.

FIGS. 4-12 illustrate various views of an ultrasonic surgical instrument 9000. In various aspects, the surgical instrument 9000 can be embodied generally as a pair of ultrasonic shears. More specifically, the surgical instrument 9000 can include a first arm 9002 pivotably connected to a second arm 9004 at a pivot area 9016 by, e.g., a fastener 9006. The surgical instrument 9000 further includes a pair of handles or eye rings 9010, 9012 disposed at the proximal ends of the first arm 9002 and the second arm 9004, respectively. The first arm 9002 includes a jaw 9008 or clamp positioned at its distal end that includes a cooperating surface 9026, which is configured to cooperate with an end effector 9054 extending distally from the second arm 9004. Actuating the first arm 9002 in a first direction causes the jaw 9008 to pivot towards the end effector 9054 and actuating the first arm 9002 in a second direction causes the jaw 9008 to pivot away from the end effector 9054. In some aspects, the cooperating surface 9026 further includes a pad constructed from a polymeric or other compliant material and engages the end effector 9054. The surgical instrument 9000 further includes a transducer assembly, such as is described above with respect to FIGS. 1-3. The transducer assembly can be arranged in, e.g., a D31 or D33 architecture. The surgical instrument 9000 further comprises a housing 9052 enclosing various components of an ultrasonic system 10 (FIG. 1), including first and second piezoelectric elements 9064 a, 9064 b of an ultrasonic transducer 9062 arranged in a D31 architecture, a transducer base plate 9050 (e.g., a transducer mounting portion) comprising flat faces on opposite sides to receive the piezoelectric elements 9064 a, 9064 b, and a waveguide 9058 that longitudinally translates vibrations from the ultrasonic transducer 9062 to the end effector 9054. The surgical instrument 9000 further comprises an electrical connector 9056 that is connectable to an ultrasonic signal generator for driving the ultrasonic transducer 9062, as described above. The waveguide 9058 can comprise a plurality of stabilizing silicone rings or compliant supports 9060 positioned at, or at least near, a plurality of nodes (i.e., points located at a minimum or zero crossing in the vibratory motion standing wave). The compliant supports 9060 are configured to dampen undesirable lateral vibration in order to ensure that ultrasonic energy is transmitted longitudinally to the end effector 9054. The waveguide 9058 extends through the housing 9052 and the second arm 9004 and terminates at the end effector 9054, externally to the housing 9052. The end effector 9054 and the jaw 9008 are cooperating elements that are configured to grasp tissue, generally functioning collectively as a clamp 9030. Moving the jaw 9008 towards the end effector 9054 causes tissue situated therebetween to contact the end effector 9054, allowing the end effector 9054 to operate against the grasped tissue. As the end effector 9054 ultrasonically vibrates against the gasped tissue, the end effector 9054 generates frictional forces that cause the tissue to coagulate and eventually sever along the cutting length of the end effector 9054.

In some aspects, the transducer base plate 9050, waveguide 9058, and end effector 9054 assembly is manufactured as a planar member. However, in various aspects, the interior channel of the housing 9052 through which the waveguide 9058 extends is non-linear, as depicted in FIG. 8, because the assembly of the pivot area 9016 at which the first arm 9002 is joined to the second arm 9004 extends into the interior of the housing 9052. When the waveguide 9058 is situated within the housing 9052 during the assembly or manufacture of the surgical instrument 900, the waveguide 9058 is bent or elastically deformed around the interiorly-projecting portion of the pivot area 9016. The interior portion of the housing 9052 is arranged such that the terminal end of the waveguide 9058, i.e., the end effector 9054, extending beyond the housing 9052 is coplanar or aligned with the jaw 9008 and/or the first arm 9002. Conversely, the proximal portion of the waveguide 9058 is not coplanar with the end effector 9054. This curved arrangement allows the waveguide 9058 to avoid the interiorly-projecting portion of the pivot area 9016, e.g., fastener 9006, while still maintaining a slim profile for the housing 9052.

The cutting length of the surgical instrument 9000 corresponds to the lengths of the end effector 9054 and the cooperating surface 9026 of the jaw 9008. Tissue that is held between the end effector 9054 and the cooperating surface 9026 of the jaw 9008 for a sufficient period of time is cut by the end effector 9054, as described above. The end effector 9054 and the corresponding portion of the jaw 9008 can have a variety of shapes. In some aspects, the end effector 9054 is substantially linear in shape, as is depicted in FIGS. 4-8. In other aspects, the end effector 9054 is curved, as is depicted in FIGS. 10-11. In any case, the portion of the jaw 9008 configured to bring tissue into contact with the end effector 9054 corresponds to the shape of the end effector 9054 so that the jaw 9008 is aligned therewith.

In some aspects of the present surgical instrument 9000, there exists a gap 9028 situated proximally to the cooperating surface 9026 of the jaw 9008. If tissue extends into the gap 9028 during the use of the surgical instrument 9000, beyond the cooperating surface 9026 of the jaw 9008, then the coagulation and cutting of this overloaded tissue will be negatively impacted because the cooperating surface 9026 of the jaw 9008 will not be forcing the overloaded tissue to remain in contact with the end effector 9054. Therefore, various aspects of the surgical instrument 9000 include features to mitigate these effects.

In one such aspect wherein the cooperating surface 9026 is shorter in length than the end effector 9054, the region of the jaw 9008 corresponding to the cooperating surface 9026 includes an indicium 9014 or indicia thereon. The indicium 9014 extends across the exterior surface of the jaw 9008 from the distal end of the cooperating surface 9026 to the proximal end thereof. Stated differently, the indicium 9014 is coextensive with the cooperating surface 9026 of the jaw 9008. As the cutting length of the surgical instrument 9000 is equivalent to the length that the end effector 9054 and the cooperating surface 9026 of the jaw 9008 overlap, the indicium 9014 thus visually indicates the cutting length of the end effector 9054 to the operator of the surgical instrument 9000. Indicating the cutting length of the surgical instrument 9000 on the side opposing the end effector 9054, i.e., on the jaw 9008 and/or first arm 9002, can be useful in situations where the operator cannot see the end effector 9054 itself, such as when the surgical instrument 9000 is being utilized to cut tissue that obscures the end effector 9054. In various aspects, the indicium 9014 includes colors, markings (e.g., geometric patterns), protrusions, surface texture, a change in geometry of the end effector 9054 and/or the jaw 9008 (e.g., a curvature), or anything that otherwise visually distinguishes the particular region of the jaw 9008 from the adjacent structure of the surgical instrument 9000. In one particular aspect, the indicium 9014 is a color. In alternative aspects wherein the end effector 9054 is shorter in length than the cooperating surface 9026 of the jaw 9008, the indicium 9014 disposed on the jaw 9008 instead corresponds in length to (i.e., is coextensive with) the end effector 9054. In still other aspects, the indicium 9014 is disposed on the end effector 9054, rather than the jaw 9008.

The housing 9052 and associated structure of the ultrasonic system can be attached to at least one of the first arm 9002 or the second arm 9004 utilizing a variety of different means known in the field. In one aspect depicted in FIGS. 1-4, the housing 9052 is fixedly attached to the second arm 9004 of the surgical instrument 9000 via a collet 9022. In other aspects, the housing 9052 can be attached via adhesives, fasteners, or mechanical connectors, such as clips. In still other aspects, the housing 9052 can be fashioned as a single structural component with at least one of the first arm 9002 or the second arm 9004 via, e.g., injection molding. In yet still other aspects, the housing 9052 can alternatively be fixedly attached to the first arm 9002 of the surgical instrument 9000.

In various aspects, the arm opposing the arm to which the housing 9052 is affixed can be removably connectable to the housing 9052. For example, in one aspect of the surgical instrument 9000 depicted in FIG. 12, the first arm 9002 is removably connectable to the housing 9052 via a first clip 9021 disposed on the first arm 9002 that engages a corresponding second clip 9020 disposed on the housing 9052. In another aspect depicted in FIGS. 4-7, the first arm 9002 is removably connectable to the housing 9052 via a slot 9025 that is configured to frictionally engage a corresponding projection or tab 9024 disposed on the housing 9052. Securing the first arm 9002 to the housing 9052 reduces the profile of the surgical instrument 9000 when it is not in use. In alternative aspects wherein the housing 9052 is fixedly connected to the first arm 9002, the housing 9052 can be removably connected to the second arm 9004 in a variety of manners, as described above.

FIGS. 13-14 illustrate side views of a surgical instrument 9000 clamping a tissue 9900, according to one aspect of this disclosure. In the depicted aspect, the surgical instrument 9000 is configured to detect when the tissue 9900 clamped by the surgical instrument 9000 is overloaded or, stated differently, when the grasped tissue 9900 extends proximally beyond the cooperating surface 9026 of the jaw 9008 and/or end effector 9054. It is desirable to detect such an occurrence for a number of different reasons. For example, when tissue 9900 is positioned in the gap 9028, rather than securely between the cooperating surface 9026 and the end effector 9054, it may not be making consistent contact with end effector 9054, which can negatively impact the performance of the surgical instrument 9000. As another example, if the tissue 9900 that the operator intends to grasp with the clamp 9030 instead enters the proximal gap 9028, the operator of the surgical instrument 9000 may be coagulating and/or cutting an unintended portion of the tissue 9900. As yet another example, if tissue 9900 moves too far proximally, it can become pinched between the first arm 9002 and the second arm 9004, causing damage to the tissue 9900 or otherwise interfering with cutting action of the surgical instrument 9000.

In this aspect, the jaw 9008 comprises a first electrode 9100 having a first electrical potential and a second electrode 9102 having a second electrical potential. The first electrode 9100 corresponds to the position of the cooperating surface 9026 of the jaw 9008. In one aspect, the first electrode 9100 is coextensive with the cooperating surface 9026. The second electrode 9102 corresponds to the position of the gap 9028. In one aspect, the second electrode 9102 is coextensive with the surface of the jaw 9008 corresponding to the gap 9028. When tissue 9900 contacts both the first electrode 9100 and the second electrode 9102, the circuit is completed and a signal is generated indicating that tissue 9900 has been detected in the proximal gap 9028 (i.e., is overloaded). The signal can include an electrical signal transmitted via a wired connection to, e.g., a controller of the surgical instrument 9000. The signal can also include a wireless signal that is received by a corresponding electronic device that is in wireless communication with the surgical instrument 9000. The signal can be utilized to provide an alert to the operator of the surgical instrument 9000, initiate an alarm, deactivate the end effector 9054, or take other corrective action.

In addition to, or in lieu of, components configured to visually indicate the cutting length of the surgical instrument, as described in relation to FIGS. 1-12, or components to detect when tissue is overloaded, as described in relation to FIGS. 13-14, various aspects of the surgical instrument 9000 can be configured to physically prevent grasped from being overloaded. Referring generally now to FIGS. 15-43, there are shown various aspects of ultrasonic surgical instruments 9000 incorporating structural features configured to serve as stops or impediments that physically prevent tissue from loading beyond, i.e., from extending proximally past, the cooperating surface 9026 and/or end effector 9054 when grasped thereby. Such components are referred to collectively as “tissue stops.” Each of the tissue stops described herein can be configured to physically obstruct or block tissue from extending proximally beyond the cooperating surface 9026 throughout the range of movement of the jaw 9008 relative to the end effect 9504.

FIGS. 15-16 illustrate various views of an ultrasonic surgical instrument 9000 incorporating a pivotable member 9150 tissue stop, according to one aspect of this disclosure. In one aspect, the pivotable member 9150 comprises a pair of opposing sides 9158 a, 9158 b and an open interior 9154. The opposing sides 9158 a, 9158 b are connected to the jaw 9008 and/or the first arm 9002 at a pivot point 9156. The open interior 9154 framed by the opposing sides 9158 a, 9158 b is greater than or equal in length to the distance from the pivot point 9156 to the distal ends of the end effector 9054 and the jaw 9008, which allows the pivotable member 9150 to pivot from a position stowed against the first arm 9002, around the distal end of the surgical instrument 9000 to a deployed position where the opposing sides 9158 a, 9158 b extend across the lateral sides of the jaw 9008 and the end effector 9054. In one aspect, when the pivotable member 9150 is in the deployed position, it is oriented generally orthogonally with respect to the end effector 9054. The pivot point 9156 can be positioned on the first arm 9002 and/or the jaw 9008 such that it is aligned with the proximal end of the cooperating surface 9026. Therefore, when the pivotable member 9150 is deployed, the opposing sides 9158 a, 9158 b extend downwardly from the pivot point 9156 along the lateral sides of the jaw 9008 and the end effector 9054 at the proximal end of the cooperating surface 9026, physically preventing tissue from extending therebeyond. The pivot point 9156 can additionally include a stop configured to prevent the pivotable member 9150 from rotating beyond a position in which it is oriented generally orthogonally when deployed.

In one aspect, the jaw 9008 and/or first arm 9002 further comprises a channel 9152 or slot that is configured to receive at least a portion of the pivotable member 9150. The depth of the channel 9152 can be, in one aspect, greater than or equal to the height of the pivotable member 9150. In such aspects, the pivotable member 9150 is flush with or recessed from the surface of the surgical instrument 9000 when in the stowed position.

FIGS. 17-19 illustrate various views of an ultrasonic surgical instrument 9000 incorporating a mechanical linkage 9170 tissue stop, according to one aspect of this disclosure. The mechanical linkage 9170 is a rigid member comprising a first end 9172 and a second end 9174. The first end 9172 is pivotably connected to an intermediate linkage 9176, which in turn is pivotably connected to the first arm 9002 adjacent to the jaw 9008. The second end 9174 is pivotably connected to the second arm 9004 adjacent to the end effector 9054. When the jaw 9008 rotates from the open position, depicted in FIG. 18, to the closed position, depicted in FIG. 19, a shelf 9178 positioned adjacently to the proximal end of the jaw 9008 contacts the first end 9172 of the linkage 9170, causing the linkage 9170 to rotate to a position wherein the linkage 9170 rests substantially flush to the proximal end of the jaw 9008. The linkage 9170 thus occupies the space between the proximal end of the jaw 9008 and the first and second arms 9002, 9004, physically preventing tissue gasped between the jaw 9008 and the end effector 9054 from extending proximally beyond the cooperating surface 9026.

FIGS. 20-22 illustrate various side views of an ultrasonic surgical instrument 9000 incorporating a deformable member 9190 tissue stop, according to one aspect of this disclosure. The deformable member 9190 is configured to elastically deform throughout the range of motion of the clamp 9030 between its open position and its closed position in order to block tissue 9900 from extending into the gap 9028. In one aspect, the deformable member 9190 comprises a tubular member constructed from an elastomeric material. The length of the tubular member can be equal to the width of the clamp 9030. The deformable member 9190 can comprise a first end 9192 that is affixed to the second arm 9004 and/or the end effector 9054 and a second end 9194 that is affixed to the first arm 9002 and/or the jaw 9008. In one aspect, the second end 9194 is attached to the first arm 9002 at a position adjacent to the proximal end of the cooperating surface 9026. When the clamp 9030 transitions to an open position, the second arm 9004 exerts a force at the first end 9192 and the first arm 9002 exerts a force at the second end 9194, which in combination causes the deformable member 9190 to expand in as the end effector 9054 and the jaw 9008 pivot away from each other. Likewise, when the clamp 9030 transitions to a closed position, the deformable member 9190 is compressed as the end effector 9054 and the jaw 9008 pivot towards each other. The deformable member 9190 thus occupies the space between the end effector 9054 and the jaw 9008 regardless of their relative positions. The ends 9192, 9194 of the deformable member 9190 can be affixed to their respective portions of the surgical instrument 9000 via, e.g., adhesives, fasteners, mechanical connectors.

FIGS. 23-26 illustrate various views of an ultrasonic surgical instrument 9000 incorporating a curved bar 9200 tissue stop, according to one aspect of this disclosure. In one aspect, the surgical instrument 9000 comprises a curved bar 9200 extending from the distal end of the second arm 9004, adjacent to the end effector 9054. The curved bar 9200 extends from the surface of the second arm 9004 oriented towards the first arm 9002, through a channel 9204 extending through the first arm 9002. The curvature of the curved bar 9200 corresponds to the rotational arc 9201 of the first arm 9002 or jaw 9008 (i.e., the arc along which a fixed point on the first arm 9002 or jaw 9008 travels as the jaw 9008 pivots between the open and closed positions), such that the first arm 9002 can pivot without obstruction from the curved bar 9200. In various aspects, the curved bar 9200 further comprises a head 9202 disposed at its distal end that has a larger width or diameter than at least a portion of the channel 9204 in which the curved bar 9200 is positioned. The head 9202 serves to limit the rotational arc 9201 of the first arm 9002 relative to the second arm 9004, preventing the curved bar 9200 from being withdrawn from the channel 9204 due to over rotation of the first arm 9002.

In various aspects, the curved bar 9200 has a width equal to at least a portion of the width of the cooperating surface 9026 or end effector 9054. As the curved bar 9200 is positioned adjacently to the proximal end of the cooperating surface 9026 and the first arm 9002 slides over the curved bar 9200 throughout the rotational arc 9201 of the first arm 9002, the curved bar 9200 thus serves as a physical obstruction between the open and closed positions of the clamp 9030 preventing grasped tissue from migrating therebeyond.

FIGS. 27-30 illustrates a perspective view of an ultrasonic surgical instrument 9000 incorporating an end effector ring 9250 tissue stop, according to one aspect of this disclosure. The ring 9250 comprises a torus or ring-shaped member including an aperture 9252 extending through the ring 9250 that is configured to receive the end effector 9054 therethrough. In one aspect, the aperture 9252 of the ring 9250 is configured to match the size and shape of the dimensions of the end effector 9054. The aperture 9252 is sized to a close tolerance of the end effector 9054 so that the ring 9250 can be slid along the length of the end effector 9054, but remains securely in place when undisturbed. When placed on the end effector 9054, the ring 9250 is configured to extend to the surface of the jaw 9008 defining the upper bound of the gap 9028 between the jaw 9008 and the end effector 9054. Therefore, when the ring 9250 is placed along the end effector 9054 proximal to the cooperating surface 9026, the ring 9250 serves as a physical barrier preventing tissue from entering the gap 9028. The ring 9250 can be constructed from, e.g., an elastomeric material.

In various aspects, the ring 9250 further comprises a clip 9256 affixed thereto that is configured to assist in securing the ring 9250 in place on the end effector 9054. In one aspect depicted in FIGS. 28-29, the clip 9256 comprises an aperture 9258, which is aligned with the aperture 9252 of the ring 9250, and a plurality of arms 9254. The arms 9254 extend orthogonally from the clip 9256 relative to the end effector 9054. The aperture 9258 of the ring 9250 is likewise configured to receive the end effector 9054 therethrough. The arms 9254 are elastically biased members defining a slot 9262 that is configured to receive a portion of the jaw 9008. When a portion of the jaw 9008 is inserted into the slot 9262, the arms 9254 frictionally engage the portion of the jaw 9008, which holds the ring 9250 in place. In another aspect depicted in FIG. 30, the clip 9256 comprises an aperture 9258, which is aligned with the aperture 9252 of the ring 9250, and a plurality of arms 9260. The arms 9260 extend longitudinally from the clip 9256 relative to the end effector 9054. The arms 9260 are elastically biased members defining a slot 9264 that is configured to receive a projection (not shown) extending from the interior surface of the jaw 9008. When the arms 9260 are clipped to the projection from the jaw 9008, the arms 9260 frictionally engage the projection, which holds the ring 9250 in place.

FIGS. 31-33 illustrate views of an ultrasonic surgical instrument 9000 incorporating a longitudinally slidable member 9270 tissue stop, according to one aspect of this disclosure. In this aspect, the surgical instrument 9000 comprises a longitudinally slidable member 9270 disposed on the end effector 9054 that is configured to transition between a first or retracted position when the clamp 9030 is opened and a second or extended position when the clamp 9030 is closed. The slidable member 9270 comprises a channel 9280 configured to receive the end effector 9054, a distal surface 9276, and an arm 9278 extending from the proximal end. The channel 9280 further comprises a spring assembly 9272 that biases the slidable member 9270 towards the retracted position. In other words, the spring assembly 9272 is configured to return the slidable member 9270 to the retracted position from the extended position. The surgical instrument 9000 further comprises a projection 9274 extending from the first arm 9002 contacts the arm 9278 of the slidable member 9270 when the jaw 9008 pivots to the closed or clamped position. The contact between the projection 9274 and the arm 9278 drives the slidable member 9270 distally along the end effector 9054, placing the slidable member 9270 in an extended position. When the longitudinally slidable member 9270 is in the extended position, the distal surface 9276 makes contact with the proximal end of the cooperating surface 9026. The surface area of the distal surface 9276 is sufficient to extend from the end effector 9054 to the lower bound of the gap 9028, thereby allowing the slidable member 9270 to serve as a physical barrier preventing tissue from extending beyond the cooperating surface 9026 when the slidable member 9270 is in the extended position. When the jaw 9008 is pivoted away from the end effector 9054 to the open position of the clamp 9030, the projection 9274 disengages from the arm 9278 and the spring assembly 9272 returns the slidable member 9270 to its retracted position.

FIGS. 34-35 illustrate side views of an ultrasonic surgical instrument 9000 incorporating a cam 9290 tissue stop in an open position, according to one aspect of this disclosure. In one aspect, the surgical instrument 9000 comprises a first arm 9002 that is pivotably connected to a second arm 9004 by a pivot pin 9296. The surgical instrument 9000 further includes a cam 9290 that is configured to translate longitudinally between a distal or extended position and a proximal or retracted position. In one aspect, the cam 9290 includes a cam pin 9298 or camming surface that is engaged with a cam slot 9294 disposed on the first arm 9002. In various aspects, the shape of the cam slot 9294 is configured to cause the cam 9290 to be translated distally (i.e., extended) when the jaw 9008 is pivoted away from the end effector 9054 and translated proximally (i.e., retracted) when the jaw 9008 is pivoted towards the end effector 9054. In one aspect, the cam slot 9294 has a curved or serpentine shape including a first ramp 9302 configured to contact the cam pin 9298 when the jaw 9008 is opened (as depicted in FIG. 35), exerting a first horizontal force on the cam pin 9298. As the cam pin 9298 is fixedly attached to the cam 9290, the first horizontal force causes the cam 9290 to translate distally. The cam slot 9294 further includes a second ramp 9304, opposing the first ramp 9302, configured to contact the cam pin 9298 when the jaw 9008 is closed (as depicted in FIG. 34), exerting a second horizontal force on the cam pin 9298. The second horizontal force exerted by the second ramp 9304 on the cam pin 9298 is oriented oppositely to the first horizontal force, which causes the cam 9290 to translate proximally.

The cam 9290 includes a leading or distal surface 9300 that is configured to serve as a physical impediment or barrier preventing tissue from extending past the cooperating surface 9026 of the jaw 9008 when the surgical instrument 9000 is being utilized to grasp tissue. When the cam 9290 is in the extended position (as depicted in FIG. 35), the distal surface 9300 of the cam 9290 is positioned adjacently to the proximal end of the cooperating surface 9026. When an operator opens the jaw 9008 to grasp tissue, the distal surface 9300 thus blocks tissue from being overloaded. Once tissue is properly loaded and the jaw 9008 is then closed, the cam 9290 retracts.

The cam 9290 further comprises a slot 9292 disposed along its length that receives the pivot pin 9296 connecting the first arm 9002 and the second arm 9004 therethrough. The slot 9292 serves three purposes. First, the slot 9292 prevents the cam 9290 from interfering with the pivotable linkage (i.e., the pivot pin 9296) between the first arm 9002 and the second arm 9004. Second, in some aspects the width of the slot 9292 is equal to a close tolerance of the diameter or width of the pivot pin 9296. The close tolerance between the width of the slot 9292 and the pivot pin 9296 limits the non-longitudinal movement of the cam 9290. Stated differently, the slot 9292 ensures that the cam 9290 translates in a linear or longitudinal manner. Third, the length of the slot 9292 can be configured to serve as an absolute limit on the degree to which the jaw 9008 can be pivoted relative to the end effector 9054. When the proximal end of the slot 9292 contacts the pivot pin 9296 as the cam 9290 moves across the pivot pin 9296, the cam 9290 is prevented from being translated further distally. When the cam 9290 is locked from translating distally, the engagement between the cam pin 9298 and the cam slot 9294 then prevents the first arm 9002 and the jaw 9008 from pivoting further.

FIGS. 36-37 illustrate perspective views of an ultrasonic surgical instrument 9000 incorporating a flexible strip 9350 tissue stop, according to one aspect of this disclosure. In one aspect, the surgical instrument 9000 comprises a flexible strip 9350 including a first end 9352 attached to the second arm 9004 adjacent to the proximal end of the end effector 9054 and a second end 9354 slidably disposed within a channel 9356 positioned on the jaw 9008. The flexible strip 9350 can be constructed from, e.g., an elastomeric material, a series of rigid members flexibly connected together, or another such material or structure that allows the flexible strip 9350 to flex or deform as the jaw 9008 moves relative to the end effector 9054. In the depicted aspect, the flexible strip 9350 is arranged such that when the jaw 9008 pivots towards the end effector 9054, the flexible strip 9350 is retracted into the channel 9356, and when the jaw 9008 pivots away from the end effector 9054, the flexible strip 9350 extends from the channel 9356. However, the second end 9354 of the flexible strip 9350 is maintained within the channel 9356 throughout the range of movement of the jaw 9008. As the flexible strip 9350 slides in and out of the channel 9356 throughout the range of movement between the open and closed positions, the flexible strip 9350 bends or flexes so that a leading portion of the flexible strip 9350 is maintained adjacently to the proximal end of the cooperating surface 9026. The flexible strip 9350 thus serves as a physical barrier preventing tissue from extending beyond the cooperating surface 9026 when the surgical instrument 9000 is in use.

FIGS. 38-40 illustrate perspective views of an ultrasonic surgical instrument 9000 incorporating a flexible strip 9350 tissue stop, according to one aspect of this disclosure. In one aspect, the surgical instrument 9000 comprises a flexible strip 9350 including a first end 9352 slidably attached to the second arm 9004 adjacent to the proximal end of the end effector 9054 and a second end 9354. In one aspect, the first end 9352 is slidably attached to the second arm 9004 by one or more rollers 9358 positioned at the first end 9352 that are slidably disposed along an interior surface of a channel 9360 extending longitudinally along the second arm 9004. In one aspect, the second end 9354 is affixed to the cooperating surface 9026 via, e.g., a living hinge. In some aspects, the flexible strip 9350 and the cooperating surface 9026 are constructed as a continuous strip of material. The flexible strip 9350 can be constructed from, e.g., an elastomeric material, a series of rigid members flexibly connected together, or another such material or structure that allows the flexible strip 9350 to flex or deform as the jaw 9008 moves relative to the end effector 9054. In the depicted aspect, the flexible strip 9350 is arranged such that when the jaw 9008 pivots towards the end effector 9054, the flexible strip 9350 is retracted into the channel 9360, and when the jaw 9008 pivots away from the end effector 9054, the flexible strip 9350 extends from the channel 9360. However, the first end 9352 of the flexible strip 9350 is maintained within the channel 9356 throughout the range of movement of the jaw 9008. As the flexible strip 9350 slides in and out of the channel 9356 throughout the range of movement between the open and closed positions, the flexible strip 9350 bends or flexes so that a leading portion of the flexible strip 9350 is maintained adjacently to the proximal end of the cooperating surface 9026. The flexible strip 9350 thus serves as a physical barrier preventing tissue from extending beyond the cooperating surface 9026 when the surgical instrument 9000 is in use.

FIGS. 41-43 illustrate perspective views of an ultrasonic surgical instrument 9000 incorporating a flexible strip 9350 tissue stop, according to one aspect of this disclosure. In one aspect, the surgical instrument 9000 comprises a flexible strip 9350 including a first end 9352 slidably attached to the second arm 9004 adjacent to the proximal end of the end effector 9054 and a second end 9354. In one aspect, the first end 9352 is slidably attached to the second arm 9004 by one or more rollers 9358 positioned at the first end 9352 that are slidably disposed along an interior surface of a channel 9360 extending longitudinally along the second arm 9004. In one aspect, the second end 9354 is affixed to the jaw 9008 via an adhesive, mechanical fastener, or other such attachment method known in the art. The flexible strip 9350 can be constructed from, e.g., an elastomeric material, a series of rigid members flexibly connected together, or another such material or structure that allows the flexible strip 9350 to flex or deform as the jaw 9008 moves relative to the end effector 9054. In the depicted aspect, the flexible strip 9350 is arranged such that when the jaw 9008 pivots towards the end effector 9054, the flexible strip 9350 is retracted into the channel 9360, and when the jaw 9008 pivots away from the end effector 9054, the flexible strip 9350 extends from the channel 9360. However, the first end 9352 of the flexible strip 9350 is maintained within the channel 9356 throughout the range of movement of the jaw 9008. As the flexible strip 9350 slides in and out of the channel 9356 throughout the range of movement between the open and closed positions, the flexible strip 9350 bends or flexes so that a leading portion of the flexible strip 9350 is maintained adjacently to the proximal end of the cooperating surface 9026. The flexible strip 9350 thus serves as a physical barrier preventing tissue from extending beyond the cooperating surface 9026 when the surgical instrument 9000 is in use.

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

Although various aspects have been described herein, many modifications and variations to those aspects may be implemented. For example, in various aspects, such as those depicted in FIGS. 4-16, the end effector is depicted as positioned below the jaw on the surgical instrument; whereas in other aspects, such as those depicted in FIGS. 17-43, the end effector is depicted as positioned above the jaw on the surgical instrument. Notably, these aspects are merely illustrative and the teachings of one type are equally applicable to another type and the various structural characteristics can be utilized interchangeably in alternative aspects. As another example, different types of end effectors may be employed. Also, where materials are disclosed for certain components, other materials may be used. The foregoing description and following claims are intended to cover all such modification and variations.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

Various aspects of the subject matter described herein are set out in the following numbered examples:

Example 1

An ultrasonic surgical instrument comprising: an end effector; a jaw movable relative to the end effector; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and an indicium coextensive with a portion of the jaw overlying the end effector.

Example 2

The ultrasonic surgical instrument of Example 1, wherein the indicia comprises a color.

Example 3

The ultrasonic surgical instrument of Example 1 or Example 2, further comprising: a first electrode; and a second electrode; wherein a tissue contacting both the first electrode and the second electrode generates a signal.

Example 4

The ultrasonic surgical instrument of Example 3, further comprising a cooperating surface disposed on the jaw, the cooperating surface aligned with the end effector, wherein the first electrode is coextensive with the cooperating surface and the second electrode positioned proximally to the cooperating surface.

Example 5

The ultrasonic surgical instrument of one or more Example 1 through Example 4, further comprising: a linkage comprising a first end fixedly attached adjacent to the end effector and a second end pivotably attached adjacent to the jaw; wherein in the jaw closed position, the linkage is configured to pivot and contact a proximal end of the jaw; and wherein in the jaw open position, the linkage is configured to pivot away from the proximal end of the jaw.

Example 6

The ultrasonic surgical instrument of one or more of Example 1 through Example 5, further comprising: a cam movably connected to the jaw via a linkage; wherein in the jaw closed position, the cam is configured to extend and contact a proximal end of the jaw; and wherein in the jaw open position, the cam configured to retract.

Example 7

The ultrasonic surgical instrument of one or more of Example 1 through Example 6, further comprising: a slidable member movable between a retracted position and an extended position, wherein in the slidable member extended position the slidable member is configured to contact a proximal end of the jaw; wherein the member is biased to the retracted position; and a projection, wherein in the jaw closed position the projection is configured to contact the spring-biased member, and wherein in the jaw closed position the projection is configured to move the slidable member to the extended position.

Example 8

The ultrasonic surgical instrument of one or more of Example 1 through Example 7, further comprising a pivotable member configured to pivot from a first position to a second position wherein the pivotable member extends across the lateral sides of the jaw and the end effector.

Example 9

The ultrasonic surgical instrument of one or more of Example 1 through Example 8, further comprising a ring configured to be fitted over the end effector.

Example 10

The ultrasonic surgical instrument of one or more of Example 1 through Example 9, further comprising an elastomeric member disposed between the end effector and the jaw, wherein in the jaw open position the elastomeric member is stretched between the end effector and the jaw, and wherein in the jaw closed position the elastomeric member is compressed between the end effector and the jaw.

Example 11

The ultrasonic surgical instrument of one or more of Example 1 through Example 10, further comprising: a first arm; wherein the jaw disposed at a distal end of the first arm; a second arm pivotably connected to the first arm; wherein the end effector disposed at a distal end of the second arm; and a bar member extending from the second arm through the first arm at a position proximal to the jaw, the bar member comprising a curvature corresponding to a rotational arc of the first arm.

Example 12

The ultrasonic surgical instrument of one or more of Example 1 through Example 11, further comprising: a flexible strip comprising: a first end fixedly attached to the jaw; and a second end; a channel configured to slidably receive the second end; wherein in the jaw closed position the second end retracts into the channel, and wherein in the jaw open position the second end extends from the channel.

Example 13

The ultrasonic surgical instrument of one or more of Example 1 through Example 12, further comprising: a housing enclosing the ultrasonic transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the ultrasonic transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing.

Example 14

An ultrasonic surgical instrument comprising: an end effector; a jaw movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and a cam movably connected to the jaw via a linkage; wherein in the jaw closed position, the cam is configured to extend towards a proximal end of the jaw; and wherein in the jaw open position, the cam is configured to retract.

Example 15

The ultrasonic surgical instrument of Example 14, further comprising: a housing enclosing the transducer assembly; a first arm; a second arm pivotably connected to the first arm; wherein the housing is fixedly connected to the first arm and removably connectable to the second arm.

Example 16

The ultrasonic surgical instrument of Example 14 or Example 15, further comprising: a first electrode; and a second electrode; wherein a tissue contacting both the first electrode and the second electrode generates a signal.

Example 17

The ultrasonic surgical instrument of one or more of Example 14 through Example 16, further comprising: a housing enclosing the ultrasonic transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the ultrasonic transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing.

Example 18

An ultrasonic surgical instrument comprising: an end effector; a jaw movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; a slidable member movable between a retracted position and an extended position, wherein in the slidable member extended position the slidable member is configured to contact a proximal end of the jaw; wherein the member is biased to the retracted position; and a projection, wherein in the jaw closed position the projection is configured to contact the spring-biased member, and wherein in the jaw closed position the projection is configured to move the slidable member to the extended position.

Example 19

The ultrasonic surgical instrument of Example 18, wherein the transducer assembly is enclosed within a housing and the housing is removably connectable to at least one of the first arm or the second arm.

Example 20

The ultrasonic surgical instrument of Example 18 or Example 19, further comprising: a first electrode; and a second electrode; wherein a tissue contacting both the first electrode and the second electrode generates a signal.

Example 21

The ultrasonic surgical instrument of example one or more of Example 18 through Example 20, further comprising: a housing enclosing the ultrasonic transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the ultrasonic transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing.

Example 22

An ultrasonic surgical instrument comprising: a first arm; a second arm pivotably connected to the first arm; a jaw disposed at a distal end of the first arm; an end effector disposed at a distal end of the second arm; wherein the jaw is movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and a bar member extending from the second arm through the first arm at a position proximal to the jaw, the bar member comprising a curvature corresponding to a rotational arc of the first arm.

Example 23

The ultrasonic surgical instrument of Example 22, wherein the transducer assembly is enclosed within a housing, which is removably connectable to at least one of the first arm or the second arm.

Example 24

The ultrasonic surgical instrument of Example 22 or Example 23, further comprising: a first electrode; and a second electrode; wherein a tissue contacting both the first electrode and the second electrode generates a signal.

Example 25

The ultrasonic surgical instrument of one or more of Example 22 through Example 24, further comprising: a housing enclosing the ultrasonic transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the ultrasonic transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing. 

The invention claimed is:
 1. An ultrasonic surgical instrument comprising: an end effector; a jaw movable relative to the end effector between a jaw open position and a jaw closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; an indicium coextensive with a portion of the jaw overlying the end effector; a first arm; wherein the jaw is disposed at a distal end of the first arm; a second arm pivotably connected to the first arm; wherein the end effector is disposed at a distal end of the second arm; and a bar member extending from the second arm through the first arm at a position proximal to the jaw, the bar member comprising a curvature corresponding to a rotational arc of the first arm.
 2. The ultrasonic surgical instrument of claim 1, wherein the indicium comprises a color.
 3. The ultrasonic surgical instrument of claim 1, further comprising: a first electrode; and a second electrode; wherein a tissue contacting both the first electrode and the second electrode generates a signal.
 4. The ultrasonic surgical instrument of claim 3, further comprising a cooperating surface disposed on the jaw, the cooperating surface aligned with the end effector, wherein the first electrode is coextensive with the cooperating surface and the second electrode is positioned proximally to the cooperating surface.
 5. The ultrasonic surgical instrument of claim 1, further comprising: a housing enclosing the transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing.
 6. An ultrasonic surgical instrument comprising: a first arm; a second arm pivotably connected to the first arm; a jaw disposed at a distal end of the first arm; an end effector disposed at a distal end of the second arm; wherein the jaw is movable relative to the end effector between an open position and a closed position; a transducer assembly comprising at least two piezoelectric elements configured to ultrasonically oscillate the end effector; and a bar member extending from the second arm through the first arm at a position proximal to the jaw, the bar member comprising a curvature corresponding to a rotational arc of the first arm.
 7. The ultrasonic surgical instrument of claim 6, wherein the transducer assembly is enclosed within a housing that is removably connectable to at least one of the first arm or the second arm.
 8. The ultrasonic surgical instrument of claim 6, further comprising: a first electrode; and a second electrode; wherein the first electrode and the second electrode are configured to generate a signal when both contact a tissue.
 9. The ultrasonic surgical instrument of claim 6, further comprising: a housing enclosing the transducer assembly; and an electrical connector disposed on the housing, the electrical connector electrically coupled to the transducer assembly and couplable to an ultrasonic signal generator; wherein the electrical connector is configured to short when contacted by fluid within the housing.
 10. The ultrasonic surgical instrument of claim 6, wherein the bar member comprises a head stopper element positioned at a distal extremity furthest from the second arm, the head stopper element configured to limit the rotational arc of the first arm relative to the second arm.
 11. The ultrasonic surgical instrument of claim 6, wherein the first arm comprises a curved channel closed on lateral sides of the first arm and open both on a side proximal to the second arm and a side distal to the second arm and opposite the side proximal to the second arm.
 12. The ultrasonic surgical instrument of claim 11, wherein the bar member extends from the second arm through the first arm by being positioned within the curved channel of the first arm.
 13. The ultrasonic surgical instrument of claim 1, wherein the bar member comprises a head stopper element positioned at a distal extremity furthest from the second arm, the head stopper element configured to limit the rotational arc of the first arm relative to the second arm.
 14. The ultrasonic surgical instrument of claim 1, wherein the first arm comprises a curved channel closed on lateral sides of the first arm and open both on a side proximal to the second arm and a side distal to the second arm and opposite the side proximal to the second arm.
 15. The ultrasonic surgical instrument of claim 14, wherein the bar member extends from the second arm through the first arm by being positioned within the curved channel of the first arm. 